A variety of elongated and generally hollow medical devices exist that can be introduced into a patient for many different purposes. For example, elongate medical devices may be used to supply therapeutic fluids, to perform diagnostic or surgical procedures, for implantation of therapeutic devices, and for the introduction of instruments. Exemplary devices include catheters, cannulae, papillotomes, sphincterotomes and the like. The medical devices have a variety of shapes and sizes, and generally include an elongated shaft ranging in length from several inches to several feet long. The diameter of the shaft of the device is usually much smaller than its length. The medical devices typically include one or more lumens extending through most or all of the length of the shaft of the device. One of the lumens may be used for insertion of a wire guide or similar device along the length of the lumen. The medical devices also generally include a distal end which may be shaped or configured as required to carry out the specific procedure for which the device is designed. For example, the distal end may include a complex curvature, adapted to the specific geometry of a target area in the body to facilitate reaching the target location or to facilitate carrying out the procedure.
These medical devices are typically packaged for sterilization and shipping. Generally, the packaging provides protection for the medical device and ensures sterility of the device upon delivery to the end user. For example, the elongate shaft of the medical device may be provided in a coiled configuration to make the device more compact for placement in a sterilization pouch and to save room for shipping and storage. These types of packages for sterilization and storage, including packages for coiled configurations, for elongate medical devices are known in the art. However, a previously unrecognized problem arises in the known packaging systems wherein the elongate medical devices become twisted or kinked before or during sterilization or storage, thus rendering these medical devices unusable for the intended medical procedure. In some packaging systems, automated feeding of the elongate medical device into a package prior to sterilization and storage may also cause twisting or kinking of the elongate portion of the device.
During the sterilization process and during storage after manufacture, the overall shape of these medical devices will often change. For example, during the ethylene gas sterilization of the medical devices, portions of these devices, such as the elongate shaft will often increase in length, twist or both, while the distal tip may lose its preformed shape. For medical devices formed from a urethane material, sterilization after manufacture and packaging may include the application of heat. However, the elevated temperature used during sterilization causes the urethane material to relax and twist. The changes in shape and length of the medical devices caused by the sterilization processes, such as ethylene gas and heat, are non-uniform and will vary between each individual medical device. These individual variations due to sterilization cannot be compensated for during the manufacturing process. Some of these changes may make it difficult for the end user to properly use the device. For example, when the lumen the medical device is twisted, insertion or removal of the wire guide may be impaired.
What is needed is an improved packaging system and method for elongate medical devices that maintains the orientation of one or more lumens or portions of the elongate shaft by orienting the elongate shaft in the packaging system prior to sterilization and storage to minimizing twisting or kinking of the shaft during sterilization, shipping and storage.